<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title></title>
</head>
<body>
<script>
  function Student(sname,sage){
    //this->new
    this.sname=sname;
    this.sage=sage;
  }
  Student.prototype.intr=function(){
    console.log(
      "I'm "+this.sname
      +",I'm "+this.sage);
  };
  Student.prototype.className=
                          "初一2班";
  var lilei=new Student("Li Lei",11);
  console.dir(lilei);
  var hmm=
    new Student("Han Meimei",12);
  console.dir(hmm);
  lilei.intr();
  hmm.intr();
  console.log(lilei.className);
  console.log(hmm.className);
  console.log(
    lilei.__proto__==hmm.__proto__
  );//true
  Student.prototype.className=
                        "初二2班";
  console.log(lilei.className);
  console.log(hmm.className);
</script>
</body>
</html>